From 02e031cbc843b010e72fcc05c76113c688b2860f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 10 Nov 2010 14:54:09 +0100 Subject: block: remove REQ_HARDBARRIER REQ_HARDBARRIER is dead now, so remove the leftovers. What's left at this point is: - various checks inside the block layer. - sanity checks in bio based drivers. - now unused bio_empty_barrier helper. - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while, but Xen really needs to sort out it's barrier situaton. - setting of ordered tags in uas - dead code copied from old scsi drivers. - scsi different retry for barriers - it's dead and should have been removed when flushes were converted to FS requests. - blktrace handling of barriers - removed. Someone who knows blktrace better should add support for REQ_FLUSH and REQ_FUA, though. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/scsi/scsi_error.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) (limited to 'drivers/scsi/scsi_error.c') diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 1de30eb83bb0..f3cf924a2cd9 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -320,19 +320,11 @@ static int scsi_check_sense(struct scsi_cmnd *scmd) "changed. The Linux SCSI layer does not " "automatically adjust these parameters.\n"); - if (scmd->request->cmd_flags & REQ_HARDBARRIER) - /* - * barrier requests should always retry on UA - * otherwise block will get a spurious error - */ - return NEEDS_RETRY; - else - /* - * for normal (non barrier) commands, pass the - * UA upwards for a determination in the - * completion functions - */ - return SUCCESS; + /* + * Pass the UA upwards for a determination in the completion + * functions. + */ + return SUCCESS; /* these three are not supported */ case COPY_ABORTED: -- cgit v1.2.3 From f281233d3eba15fb225d21ae2e228fd4553d824a Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Tue, 16 Nov 2010 02:10:29 -0500 Subject: SCSI host lock push-down Move the mid-layer's ->queuecommand() invocation from being locked with the host lock to being unlocked to facilitate speeding up the critical path for drivers who don't need this lock taken anyway. The patch below presents a simple SCSI host lock push-down as an equivalent transformation. No locking or other behavior should change with this patch. All existing bugs and locking orders are preserved. Additionally, add one parameter to queuecommand, struct Scsi_Host * and remove one parameter from queuecommand, void (*done)(struct scsi_cmnd *) Scsi_Host* is a convenient pointer that most host drivers need anyway, and 'done' is redundant to struct scsi_cmnd->scsi_done. Minimal code disturbance was attempted with this change. Most drivers needed only two one-line modifications for their host lock push-down. Signed-off-by: Jeff Garzik Acked-by: James Bottomley Signed-off-by: Linus Torvalds --- drivers/scsi/scsi_error.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers/scsi/scsi_error.c') diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index f3cf924a2cd9..824b8fc03ce5 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -773,17 +773,15 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd, struct Scsi_Host *shost = sdev->host; DECLARE_COMPLETION_ONSTACK(done); unsigned long timeleft; - unsigned long flags; struct scsi_eh_save ses; int rtn; scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes); shost->eh_action = &done; - spin_lock_irqsave(shost->host_lock, flags); scsi_log_send(scmd); - shost->hostt->queuecommand(scmd, scsi_eh_done); - spin_unlock_irqrestore(shost->host_lock, flags); + scmd->scsi_done = scsi_eh_done; + shost->hostt->queuecommand(shost, scmd); timeleft = wait_for_completion_timeout(&done, timeout); -- cgit v1.2.3 From 459dbf72e4d2b4aa13620e6b70d54f098547bf13 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Wed, 17 Nov 2010 10:10:57 -0600 Subject: [SCSI] Eliminate error handler overload of the SCSI serial number The error handler is using the test cmd->serial_number == 0 in the abort routines to signal that the command to be aborted has already completed normally. This design was to close a race window in the original error handler where a command could go through the normal completion routines after it timed out but before error handling was started. Mike Anderson pointed out that when we converted our timeout and softirq completions, we picked up atomicity here because the block layer now mediates this with the REQ_ATOM_COMPLETE flag and guarantees that *either* the command times out or our done routine is called, but ensures we can't get both occurring. That makes the serial number zero check redundant and it can be removed. Signed-off-by: James Bottomley --- drivers/scsi/scsi_error.c | 26 ++------------------------ 1 file changed, 2 insertions(+), 24 deletions(-) (limited to 'drivers/scsi/scsi_error.c') diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 824b8fc03ce5..30ac116186f5 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -615,7 +615,7 @@ static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd) return rtn; } -static int __scsi_try_to_abort_cmd(struct scsi_cmnd *scmd) +static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd) { if (!scmd->device->host->hostt->eh_abort_handler) return FAILED; @@ -623,31 +623,9 @@ static int __scsi_try_to_abort_cmd(struct scsi_cmnd *scmd) return scmd->device->host->hostt->eh_abort_handler(scmd); } -/** - * scsi_try_to_abort_cmd - Ask host to abort a running command. - * @scmd: SCSI cmd to abort from Lower Level. - * - * Notes: - * This function will not return until the user's completion function - * has been called. there is no timeout on this operation. if the - * author of the low-level driver wishes this operation to be timed, - * they can provide this facility themselves. helper functions in - * scsi_error.c can be supplied to make this easier to do. - */ -static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd) -{ - /* - * scsi_done was called just after the command timed out and before - * we had a chance to process it. (db) - */ - if (scmd->serial_number == 0) - return SUCCESS; - return __scsi_try_to_abort_cmd(scmd); -} - static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd) { - if (__scsi_try_to_abort_cmd(scmd) != SUCCESS) + if (scsi_try_to_abort_cmd(scmd) != SUCCESS) if (scsi_try_bus_device_reset(scmd) != SUCCESS) if (scsi_try_target_reset(scmd) != SUCCESS) if (scsi_try_bus_reset(scmd) != SUCCESS) -- cgit v1.2.3